Pathology is the specialized scientific study of the nature of disease and the medical practice of diagnosis of those diseases. Disease is often manifested in anatomical changes which can be visually determined. Pathologists, whether surgical, cytopathological, forensic, veterinary or other, view these changes from a normal state and make a diagnosis of the disease state. For example, cancer is diagnosed by visually identifying the structural alteration of cells. In order to simplify and describe the disease, many common cancer types are graded based on the severity or aggressive phenotype of the disease. The amount of phenotypic change from normal is described in multiple grading systems including Gleason (prostate), Nottingham (breast), Fuhrman (kidney), etc.
Each of these specialized grades includes a small number of visually identifiable criteria on the hematoxylin and eosin stained microscope slide. Several tumor types are simply graded I-IV, and are based cellular differentiation (i.e., how different the cells look compared to normal). Other factors that may be considered, depending on the tumor type, are structural formation and cellular proliferation (growth rate). The histological grade often has a profound influence on clinical decision making. This practice has been traced back to von Hansemann in the 1890s. Many of the grading systems, such as the Nottingham Score for breast cancer, are as simple as three visual clues and have remained wholly unchanged since the 1920s.
Unfortunately, discrepancies have arisen between groups of pathologists on a series of equivocal cases. This is due in large part to the challenging estimation and judgment calls which need to be made under stress. For example, pathologists may use a number of properties in deciding the nature of a cell. These properties often do not have a rigid definition. Thus, a pathologist provides a pathological decision based on the pathologist's particular experience.
However, with the advent of digital histological slide scanning (1999), massively powerful computational power and robust and reliable algorithms, novel methods are being sought to grade disease states and more precisely grade many common cancer types.
Digital pathology takes advantage of high computing efficiency and large volumes of available computational storage to create digital images of glass microscopy slides enabling a virtual microscopy to outfit the pathologist's toolbox. Automated slide scanners provide pathology departments with the high throughput tools necessary to capture tens of thousands of whole slide images every year. Slide scanners automate repeatable imaging conditions for whole slides, which enables a clinic to digitally image slides and make these digital images available to all pathologists within each network system.
While high-throughput slide scanners area generally available for pathology laboratories, desktop single slide scanners are not common. Desktop scanners would enable the individual pathologist to scan slides at a touch of a button and could be integrated with specialized software tools to establish a one-stop workflow for reliable imaging, diagnosis, quantification, management, and sharing of their own digital pathology library.